Process for preparing light transmissive electromagnetic wave shielding material, light transmissive electromagnetic wave shielding material and display filter

Abstract

The present invention provides a process for preparing a light transmissive electromagnetic wave shielding material having an excellent light transmissive property, an excellent electromagnetic wave shielding property, an excellent appearance property and an excellent legibility by a simple method. A process for the preparation of a light transmissive electromagnetic wave shielding material comprising; (A1) printing a pretreatment agent for electroless plating comprising a composite metal oxide and/or a composite metal oxide hydrate and a synthetic resin in a mesh pattern on a transparent substrate 11 to form a mesh-patterned pretreatment layer 12, and (A3) subjecting the pretreatment layer 12 to electroless plating to form a mesh-patterned metal conductive layer on the pretreatment layer 13.

1 . A process for the preparation of a light transmissive electromagnetic wave shielding material comprising;
 printing a pretreatment agent for electroless plating comprising a composite metal oxide and/or a composite metal oxide hydrate and a synthetic resin in a mesh pattern on a transparent substrate to form a mesh-patterned pretreatment layer, and   subjecting the pretreatment layer to electroless plating to form a mesh-patterned metal conductive layer on the pretreatment layer.   
   
   
       2 . A process as defined in  claim 1 , wherein the composite metal oxide and the composite metal oxide hydrate comprise at least two metallic element selected from the group consisting of Pd, Ag, Si, Ti and Zr. 
   
   
       3 . A process as defined in  claim 1 , wherein the composite metal oxide hydrate has a following formula (I):
   M 1   x .M 2 O 2   .n (H 2 O)  (I)   in which M 1  represents Pd or Ag, M 2  represents Si, Ti or Zr, x is 1 when M 1  is Pd, x is 2 when M 1  is Ag, n is an interger of from 1 to 20.   
   
   
       4 . A process as defined in  claim 1 , wherein the average particle diameter of the composite metal oxide and/or the composite metal oxide hydrate is in the range of from 0.01 to 10 μm. 
   
   
       5 . A process as defined in  claim 1 , wherein the amount of the composite metal oxide and/or the composite metal oxide hydrate is in the range of from 10 to 80 parts by weight based on 100 parts by weight of the synthetic resin. 
   
   
       6 . A process as defined in  claim 1 , wherein the synthetic resin is at least one selected from the group consisting of acrylic resin, polyester resin, polyurethane resin, vinyl chloride resin and ethylene-vinyl acetate copolymer. 
   
   
       7 . A process as defined in  claim 1 , wherein the synthetic resin has a functional group having an active hydrogen at its molecular end. 
   
   
       8 . A process as defined in  claim 7 , wherein the functional group having the active hydrogen is at least one selected from the group consisting of a hydroxyl group, a carbonyl group and an amino group. 
   
   
       9 . A process as defined in  claim 1 , wherein the amount of the synthetic resin is in the range of from 10 to 40% by weight based on the total amount of the pretreatment agent for electroless plating. 
   
   
       10 . A process as defined in  claim 1 , wherein the pretreatment agent for electroless plating further comprises an inorganic fine particle. 
   
   
       11 . A process as defined in  claim 10 , wherein the inorganic fine particle is at least one fine particle selected from the group consisting of silica particle, calcium carbonate particle, carbon particle, alumina particle, talc particle, mica particle, glass flake, metallic whisker, ceramic whisker, calcium sulfate whisker and smectite. 
   
   
       12 . A process as defined in  claim 1 , wherein the pretreatment agent for electroless plating further comprises a thixotropic agent. 
   
   
       13 . A process as defined in  claim 1 , wherein the pretreatment agent for electroless plating further comprises a black coloring agent. 
   
   
       14 . A process as defined in  claim 13 , wherein the black coloring agent is at least one selected from the group consisting of carbon black, titanium black, black iron oxide, black lead and activated carbon. 
   
   
       15 . A process as defined in  claim 1 , wherein the pretreatment agent for electroless plating is printed by gravure printing. 
   
   
       16 . A process as defined in  claim 1 , wherein the pretreatment agent for electroless plating is printed in the mesh pattern on the transparent substrate and then dried at a temperature of 80 to 160° C. 
   
   
       17 . A process as defined in  claim 1 , wherein the pretreatment layer has a line width of from 1 to 40 μm, an aperture ratio of from 50 to 95% and a line pitch of from 50 to 1000 μm. 
   
   
       18 . A process as defined in  claim 1 , wherein a thickness of the pretreatment layer is in the range of from 0.01 to 3 μm. 
   
   
       19 . A process as defined in  claim 1 , wherein the pretreatment layer is reduced before the pretreatment layer is subjected to electroless plating. 
   
   
       20 . A process as defined in  claim 19 , wherein the pretreatment layer is reduced by immersing the transparent substrate having the pretreatment layer in a solution comprising a reducing agent. 
   
   
       21 . A process as defined in  claim 20 , wherein the reducing agent is at least one selected from the group consisting of amino borane, dimethyl amino borane, sodium hypophosphite, hydroxylamine sulphate, hydrosulfite and formalin. 
   
   
       22 . A process as defined in  claim 20 , wherein the amount of the reducing agent in the solution comprising the reducing agent is in the range of from 0.01 to 200 g/L. 
   
   
       23 . A process as defined in  claim 1 , wherein the metal used in the electroless plating is silver, copper or aluminum. 
   
   
       24 . A process as defined in  claim 1 , wherein the pretreatment layer is further subjected to electrolytic plating after completion of the electroless plating. 
   
   
       25 . A process as defined in  claim 1 , which further comprising;
 subjecting the metal conductive layer to a blackening treatment to form a blackening treatment layer on at least a part of a surface of the metal conductive layer.   
   
   
       26 . A process as defined in  claim 25 , wherein the blackening treatment is carried out by subjecting the metal conductive layer to an oxidation treatment or a sulfurization treatment. 
   
   
       27 . A process as defined in  claim 25 , wherein the blackening treatment is carried out by black plating of the metal conductive layer with an alloy comprising at least one metal selected from the group consisting of nickel, zinc and chromium. 
   
   
       28 . A light transmissive electromagnetic wave shielding material obtained by the process described in  claim 1 . 
   
   
       29 . A light transmissive electromagnetic wave shielding material comprising a transparent substrate, a mesh-patterned pretreatment layer formed on the transparent substrate and a mesh-patterned metal conductive layer formed on the pretreatment layer,
 wherein the pretreatment layer is formed by using a pretreatment agent for electroless plating comprising a composite metal oxide and/or a composite metal oxide hydrate and a synthetic resin.   
   
   
       30 . A light transmissive electromagnetic wave shielding material as defined in  claim 29 , wherein a blackening treatment layer is formed on at least a part of a surface of the metal conductive layer. 
   
   
       31 . A display filter comprising the light transmissive electromagnetic wave shielding material described in  claim 28 .